What is a meteorite? And what is an asteroid?

Small pieces of space debris such as parts of asteroids or parts of comets
on a collision course with earth are called meteoroids.

When meteoroids enter the earth’s atmosphere they are called meteors.

Most meteors burn up in the atmosphere, but if they survive and strike the
surface of the earth – as the object or objects in Russia may have – they are
called meteorites.

A comet, by the way, is an object consisting of a central
mass surrounded by dust and gas that may form a tail, orbiting a star, usually
in an eccentric orbit.

Good morning. A meteor streaked across the sky above the Ural Mountains in Russia this
morning, injuring
more than 400 people, in the last report injuring around 1,200 people many hurt by broken glass, and causing explosions.

Fragments of the meteor fell in a thinly populated area of the Chelyabinsk region, the
Russian Emergency Ministry said in a statement.

Reports conflicted on what exactly happened in the clear skies. A
spokeswoman for the Emergency Ministry, Irina Rossius, told the Associated
Press that there was a meteor shower, but another ministry spokeswoman, Elena
Smirnikh, was quoted by the Interfax news agency as saying it was a single
meteor.

A space rock, which the Russian Academy of Sciences estimates weighed about 10
tonnes. Videos show a bright trail streaking through the sky, which is the object
burning up as it entered the Earth's atmosphere. The rock hit the atmosphere at
a speed of at least 54,000km/h (33,000mph), compressing the air in its path and
heating it to thousands of degrees, which gives off light. The sharp
compression of the air creates a shock wave, which is heard as a sonic boom in
many of the videos.

Was it one meteor or a shower?

Footage clearly shows a single object streaking across the sky, but it is
believed the rock shattered some 18-32 miles (30-50km) above ground. Some videos
show a sudden brightening as the body fragmented during its fiery passage
through the atmosphere.

How rare is this sort of event?

Around 40,000 tonnes of space rocks fall to Earth every year, mostly in the
form of dust and relatively small meteorites. The last time something major
struck the Earth was in 1908, when an asteroid about 50 metres across exploded
in the air above the Tunguska region of Siberia.
It flattened forests over an area of hundreds of square miles.
Friday morning's event was a tiny fraction of this magnitude. Something like
this probably happens every decade but usually takes place over an unpopulated
area.

Has anyone ever been killed by a meteorite?

No one is previously recorded to have been killed by a meteorite falling
from the sky. There are stories of a dog being killed in Egypt in 1911 and a boy being hit but not
seriously injured in Uganda
in 1992. Most of the Earth's surface is uninhabited by humans, so meteorites
usually fall over desolate areas or the oceans.

What's the difference between an asteroid, a meteor, a meteorite and a
meteoroid?

Astronomers love their definitions. A meteoroid is anything in orbit around
the sun that is smaller than 10 metres. It becomes known as an asteroid above
this size and up to about 1,000 kilometres. A meteor is a speck of dust that
burns up in the atmosphere creating a shooting star. A meteorite is a larger
fragment, from pebble to boulder-sized, that survives to strike the surface of
the Earth.

These definitions are blurring, however. Almost everyone it seems is using
the word meteor to describe the object that hit Russia. Blame Sean Connery. Back in
1979, he starred in a disaster movie about an asteroid that was to strike
Earth. They called the movie Meteor.

Why did we not see this coming?

The Russian meteorite hit during the daytime. The glare of the sun masked
its approach, like a fighter pilot using the sun to blind an enemy to the
attack. There could be thousands of asteroids that orbit closer to the sun than
the Earth, approaching our planet only occasionally and always from "out
of the sun". They are virtually impossible to spot from Earth because they
are always masked by daylight. Only a space telescope could see these
effectively. The European Space Agency's Gaia mission will help discover more
of these asteroids.

Is it connected with the asteroid close pass on Friday night?

No, the Royal Astronomical Society in London
and the European Space Agency in Darmstadt,
Germany, both
say that the approach of Friday morning's strike is unrelated to the approach
of space rock 2012 DA14, which will draw extremely close to Earth on
Friday night. According to Nasa's Near-Earth Object Observation Programme, an
asteroid like 2012 DA14 flies this close on average only once every 40 years –
although it will still be some 17,100 miles above our heads. Nevertheless, this
is closer to the Earth than many artificial satellites.

What do we do if we spot something big heading for Earth?

A recently formed working group of the United Nations Committee on the
Peaceful Uses of Outer Space would be called into session. Known as the space
mission planning advisory group, it is composed of scientists from Nasa, the
European Space Agency and the world's other space agencies. The group would
immediately meet to advise on the best strategy for dealing with the asteroid.
It would also advise on who has the expertise to build the different parts of
the necessary spacecraft, and who should pay for it. Then it would pass the
decision into the hands of politicians.

Are any regions of Earth more at risk than others?

No. Incoming asteroids and meteoroids can come from any direction.
Additionally, the Earth rotates once a day, presenting every hemisphere to the
different directions of space.

Will Friday's impact have any after-effect?

Friday's impact was certainly not enough to knock the Earth off its axis,
nor imperil telecommunications networks. The shockwave was compressed air
rather than the electromagnetic pulse (EMP) created by nuclear weapons and
solar flares. Neither is there a real risk of alien death viruses. Meteorites
fall to Earth all the time – none has brought space bugs yet. Although there
are theories that microbes could hitch rides on space rocks, there is no
incontrovertible evidence that this is a widespread phenomenon.

Is it connected to the flyby? A lot of folks would say “no”. Personally,
I’ve always kind of liked the idea that there are streams of asteroid debris –
so you can have smaller stuff that precede and trail a bigger object. It seems
like an awful big coincidence if it’s not connected.

But Simon O’Toole, an astronomer at the Australian Astronomical Observatory,
said he was “not so sure”.

He added that there was no confirmation that the meteorites had exploded:
“so far the confirmed damage was almost certainly caused by a shock wave as the
object broke the sound barrier”, he said, adding:

If this was a meteor entering the atmosphere, it’s a stark reminder of how
vulnerable we are and why we need to monitor the skies very closely for
potentially larger objects.

Why are there so many videos from people's cars?

Anyone who has ever seen one of those YouTube video compilations of
terrifyingly dangerous Russian drivers will know that every Russian driver
seems to have a camera mounted on his or her dashboard. But why?

In Russia,
everyone should have a camera on their dashboard. It’s better than keeping a
lead pipe under your seat for protection (but you might still want that lead
pipe) ...

Psychopaths are abundant on Russian roads. You best not cut anyone off or
undertake some other type of maneuver that might inconvenience the 200-pound,
six-foot-five brawling children you see on YouTube hopping out of their SUVs
with their dukes up ... These fights happen all the time and you can’t really
press charges. Point to your broken nose or smashed windows all you want. The
Russian courts don’t like verbal claims. They do, however, like to send people
to jail for battery and property destruction if there’s definite video proof
...

Dash-cam footage is the only real way to substantiate your claims in the
court of law. Forget witnesses. Hit and runs are very
common and insurance companies notoriously specialize in denying claims.
Two-way insurance coverage is very expensive and almost completely unavailable
for vehicles over ten years old–the drivers can only get basic liability.

She adds that there are moments of humanity among the crashes, but basically
"aside from the kindness of strangers, it’s just you and that little
gadget versus the hell that is the other people on the road".

What caused the explosion?

Authorities in Chelyabinsk
said the blast (which
you can hear clearly on this video) had been heard at an altitude of 10,000
metres (32,800ft), suggesting it occurred when the meteor or meteors entered
the earth’s atmosphere.

As the meteorites shot across the sky, they sent fireballs crashing to
earth. The shockwave from the explosion when the meteor entered the earth's
atmosphere smashed windows, injuring 400 people, three of them seriously,
buckled shop fronts, set off car alarms and affecting mobile phone signals. A
wall was damaged at the Chelyabinsk Zinc Plant but there was no environmental
threat, a plant spokeswoman said.

Reader Stuart
Forbes sends this video, which shows the
meteorites streaking across the sky at 4min 40sec and the sound of the
explosion and shockwave at 7min.

Residents in Chelyabinsk
heard the explosion at about 9.20am local time (5.20am GMT), saw a bright light
and felt a shockwave, according to Reuters.

Viktor Prokofiev, 36, a resident of Yekaterinburg in the Urals Mountains,
said:

I was driving to work, it was quite dark, but it suddenly became as bright
as if it was day. I felt like I was blinded by headlights.

Andrei, a resident of Chelyabinsk,
told Reuters:

I was standing at a bus stop, seeing off my girlfriend. Then there was a
flash and I saw a trail of smoke across the sky and felt a shockwave that
smashed windows.

Mengenai Saya

Facebook

kediri international school

Casinos are known for hosting live betting activities. by getting best blackjack online from reliable entities one can gain a great benefit. The US has banned gambling in an online casino. graphic counters